Flight control for aeroplanes



Sept. 6, 1932- R. c. STRUBLE FLIGHT CONTROL FOR AEQROPLANES Filed May 24, 1930 INVENTOR fiOBE/TT G. firm/51.5

ATTOR N EY Patented Sept. 6, 1932 UNITED STATES PATENT OFFICE ROBERT C. STRUBLE, OF SEATTLE, WASHINGTON, ASSIGNOR TO B. C. STRUBLE COM- IPANY, INQ, OF SEATTLE, WASHINGTON, A CORPORATION OF WASHINGTON FLIGHT CONTROL FOR AEROFLANES Application filed May 24, 1930. Serial No. 455,169.

This invention relates to flight control mechanism for air craft of the power driven, heavier than air types of construction, and has reference in particular to means for automatically maintaining an airplane on an even keel without requiring the constant attention of the pilot.

It is the principal object of this invention to provide means for the above purpose whereby the stick which controls action of the ailerons and elevators is placed under the control of solenoids and the circuits for these are closed or opened by the action of gyroscopically actuated device in such manner as to automatically maintain the plane on an even keel.

More specifically stated, the present inven- I tion resides in the use of two gyroscopic devices for controlling the solenoid circuits; this system being an improvement over that shown inmy co-pending application, filed on December 9, 1929, under Serial No. 412,616.

In accomplishin these and other objects of the invention, have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawing, wherein-- Fig. 1 is a diagrammatic view, showing in perspective, the .parts of an airplane with which the present mechanism is associated and the control devices and wiring connections between the control devices and solenoids.

Fig. 2 is the wiring diagram.

Fig. 3 is a cross sectional view of one of the gyroscopic devices.

Fig. 4 is an end view of the same.

Fig. 5 is a view in perspective showing the angular relationship of the axes of the two roscopic devices.

Re erring more in detail to the drawing In Fig. 1, which shows only the essential parts of an airplane in connection with the present mechanism, 1 and 2 designate the ailerons which are hingedly mounted by the wings of'the airplane at opposite sides of the longitudinal center line of the plane, and 3 and 4 designate the elevators at the rear end of the fuselage; these parts also are hingedly attached in the usual manner and like the accordingly. At its ends, the shaft 7 is provided with cross arms 1010' and these are connected at their upper and lower ends by means of crossed cables 11 and 12 with arms 13 and 14 which are fixed to and, respectively, extend upwardly and downwardly from the elevators 3 and 4 so that, through this cable connection, swinging of the stick, or lever 5, forwardly will cause the elevators to be tilted downwardly and, likewise, swinging of the stick rearwardly will cause them to be tilted upwardly.

The ailerons 1 and 2 are actuated by lateral movement of thestick. As shown in Fig. 1, a cable 16 is attached to the stick above its pivot point 6 and is extended through suitable guides or pulleys 17 to an arm 18 extended downwardly from aileron 2. Another cable 19 connects an arm 20, ex-

.tending upwardly from the aileron 2, with an arm 21 extended upwardly from aileron 1, and a cable 22 extends from the stick to a downwardly extended arm 23 on the aileron 2; the various cable connections being such that tilting of the lever 5 toward either side causes the aileron on that side to be inclined upwardly and the one at the opposite side to be inclined downwardly as is the usual method of control.

Automatic control of the stick 5 for the purpose of maintaining the plane on an even keel is accomplished according to the present invention by use of a plurality of solenoids 24 which are disposed at opposite sides and forwardly and rearwardly of the lower end portion 5a of the stick 5 which extends below the supporting crossshaft 7. The solenoids aredi-sposed radially of the stick as best shown in Figs. 1 and 2, and each has a sliding core bar 25 operatively connected by a link 26 with the lower end portion of the lever 5. As here shown, each solenoid employs two separate coils in end to end relation so that in reality there are two solenoids with a core bar common to both; the inner coils being designed to move the bars 25 to a certain extent and the outer coils to move them toa .still farther extent. For clarity the inner coils have been designated by reference numerals 24a.

In conjunction with the several solenoids, I employ two gyroscopically controlled devices for controlling the delivery, of electric current to the solenoids.

Each device consists of a closed housing 30 in which a yoke 31 is pivotally mounted by means of trunnions 32-32 at its ends which are rotatable in suitable bearings 33 in opposite end walls of the housing. A heavy gyroscopic wheel 35 is rotatably mounted on a cross shaft 36 in the yoke and the wheel has impeller fins 37 about its periphery.

On one end of the yoke outside the housing is a depending switch arm 38, normally in vertical position as in Fig. 4, and adapted, when the housings swings relative to the arm to engage with contacts 39 arranged at opposite sides of the vertical line and carried in a block of insulation 40.

The housings for the two gyroscopic devices are rigidly supported from a frame part of the plane at any suitable position and in such manner that when the plane is on an even keel or in true horizontal flight, the axes of the yokes 31 will lie in horizontal planes. And the housings are also placed in such po sitions that the axes of the two yokes are at right angles to each other and one is directed in the longitudinal direction of the plane and the other transversely thereto.

Entering the top of the housings are tubes 42 connected at their outer ends with venture tubes 43 for creating an outward suction of air from the housings incident to passage of air through the venture. Air ports 44 are arranged in the housing walls in such relation to the g'yroscopic wheels that the inflow of air, incident to suction-created by flight of the plane, will impinge the fins of the wheels and will cause the wheels to rotate at a high speed. In accordance with the gyroscopic principle the gyroscopic wheels maintain their vertical position regardless of tilting laterally or longitudinally of the axis and therefore should the plane tilt laterally toward either side, the switch arm 38 of the control device associated with the ailerons, will engage with contacts 89 at that side. Likewise, downward or upward nosing of the plane will cause the switch arm 39 of the control device associated with the elevators to be engaged with the contacts 39 of that device.

In Figs. 1 and 2, I have designated a source of electricity at one side by a wire 46 with a control switch 47, and this is connected by wires 48 and 49 with the switch arms 38 of the two control devices. The contacts 37 of the control device which is associated with the ailerons are connected with the solenoids at opposite sides of the stick 5; that is, the two contacts at the left side of the housing are connected by wires 50 and 51 with the coils 24 and 24a of the corresponding solenoid 24 and those at the opposite side are likewise connected by wires 52 and 53 with the opposite solenoid. In like manner the contacts 39 of the control device associated with the elevators is connected with the solenoids forwardly and rearwardly of the stick 5. As shown in Figs. 1 and 2, the two forward contacts are connected by wires 55 and 56 with the two coils of the forward solenoid set, and the two rearward contacts are connected by wires 57 and 58 with the two coils of the rearward solenoid set.

lVith the device so constructed, it will operate as follows:

Assuming that the plane tilts laterally, this causes a corresponding tilting of the rearward housing 30 containing the gyroscopic yoke that extends longitudinally of the plane, with a resultant relative movement of contact arm 38 to engage a contact 39 and thereby close a circuit through one or the other of the lateral solenoids 24 dependent on the direction and extent of tilting to effect movement of the stick 5 to bring the ship back to level position. Likewise, tilting of the plane lengthwise causes a similar action to take place between the arm 38 of the other forward gyroscopic device to close a circuit through the proper solenoid to actuate the stick to bring the plane back to an even keel.

Having thus described my invention what I claim as new therein and desire to secure by Letters-Patent, is:

In an airplane or the like, the combination with a control member that is movable in one direction to vary the elevation of the airplane and movable in another direction to effect lateral turning thereof, of gyroscopic devices operable respectively to actuate the control member for changing the elevation and lateral direction of the airplane; each of the gyroscopic devices including a rotatable driving member and separate means for the gyroscopic devices whereby slip stream air currents operate to cause delivery of air against the rotatable driving members to rotate them to functionally actuate the said gyroscopic devices.

Signed at Seattle, Washington, this 7th day of March 1930.

ROBERT C. STRUBLE. 

